Nonthermal phase transitions in metals
| Autor: | Igor Milov, Nikita Medvedev |
|---|---|
| Přispěvatelé: | XUV Optics |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Phase transition
Materials science Phonon lcsh:Medicine 02 engineering and technology 01 natural sciences Article Metal Lattice (order) 0103 physical sciences Thermal Irradiation lcsh:Science 010306 general physics Multidisciplinary lcsh:R 021001 nanoscience & nanotechnology Phase transitions and critical phenomena Chemical physics visual_art Hardening (metallurgy) visual_art.visual_art_medium lcsh:Q 0210 nano-technology Applied optics Excitation |
| Zdroj: | Scientific reports, 10(1):12775. Nature Publishing Group Scientific Reports Scientific Reports, Vol 10, Iss 1, Pp 1-9 (2020) |
| ISSN: | 2045-2322 |
| Popis: | It is well known that sufficiently thick metals irradiated with ultrafast laser pulses exhibit phonon hardening, in contrast to ultrafast nonthermal melting in covalently bonded materials. It is still an open question how finite size metals react to irradiation. We show theoretically that generally metals, under high electronic excitation, undergo nonthermal phase transitions if material expansion is allowed (e.g. in finite samples). The nonthermal phase transitions are induced via an increase of the electronic pressure which leads to metal expansion. This, in turn, destabilizes the lattice triggering a phase transition without a thermal electron-ion coupling mechanism involved. We find that hexagonal close-packed metals exhibit a diffusionless transition into a cubic phase, whereas metals with a cubic lattice melt. In contrast to covalent solids, nonthermal phase transitions in metals are not ultrafast, predicative on the lattice expansion. |
| Databáze: | OpenAIRE |
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